Recent advances in high resolution scanning electrochemical microscopy of living cells – A review

This review discusses advances in the field of high resolution scanning electrochemical microscopy (HR-SECM) and scanning ion conductance microscopy (SICM) to study living cells. Relevant references from the advent of this technique in the late 1980s to most recent contributions in 2012 are presented with special discussion on high resolution images. A clear progress especially within the last 5 years can be seen in the field of HR-SECM. Furthermore, we also concentrate on the intrinsic properties of SECM imaging techniques e.g. different modes of image acquisition, their advantages and disadvantages in imaging living cells and strategies for further enhancement of image resolution, etc. Some of the recent advances of SECM in nanoimaging have also been discussed which may have potential applications in high resolution imaging of cellular processes.     

High quality drug screening by capillary electrophoresis: A review

High quality assays are needed in drug discovery to reduce the high attrition rate of lead compounds during primary screening. Capillary electrophoresis (CE) represents a versatile micro-separation technique for resolution of enzyme-catalyzed reactions, including substrate(s), product(s), cofactor(s) and their stereoisomers, which is needed for reliable characterization of biomolecular interactions in free solution. This review article provides a critical overview of new advances in CE for drug screening over the past five years involving biologically relevant enzymes of therapeutic interest, including transferases, hydrolases, oxidoreductases, and isomerases. The basic principles and major configurations in CE, as well as data processing methods needed for rigorous characterization of enzyme inhibition are described. New developments in functional screening of small molecules that modulate the activity of disease-related enzymes are also discussed. Although inhibition is a widely measured response in most enzyme assays, other important outcomes of ligand interactions on protein structure/function that impact the therapeutic potential of a drug will also be highlighted, such as enzyme stabilization, activation and/or catalytic uncoupling. CE offers a selective platform for drug screening that reduces false-positives while also enabling the analysis of low amounts of complex sample mixtures with minimal sample handling.     

Dynamically adaptive real-time disparity estimation hardware using iterative refinement

The computational complexity of disparity estimation algorithms and the need of large size and bandwidth for the external and internal memory make the real-time processing of disparity estimation challenging, especially for High Resolution (HR) images. This paper proposes a hardware-oriented adaptive window size disparity estimation (AWDE) algorithm and its real-time reconfigurable hardware implementation that targets HR video with high quality disparity results. Moreover, an enhanced version of the AWDE implementation that uses iterative refinement (AWDE-IR) is presented. The AWDE and AWDE-IR algorithms dynamically adapt the window size considering the local texture of the image to increase the disparity estimation quality. The proposed reconfigurable hardware architectures of the AWDE and AWDE-IR algorithms enable handling 60 frames per second on a Virtex-5 FPGA at a 1024×768 XGA video resolution for a 128 pixel disparity range.     

Protection against soft errors in the space environment: A finite impulse response (FIR) filter case study

The problem of radiation is a key issue in Space applications, since it produces several negative effects on digital circuits. Considering the high reliability expected in these systems, many techniques have been proposed to mitigate these effects. However, traditional protection techniques against soft errors, like Triple Modular Redundancy (TMR) or EDAC codes (for example Hamming), normally result in a significant area and power overhead. In this paper we propose a specific technique to protect digital finite impulse response (FIR) filters applying the “system knowledge”. This means to study and use the singularities in their structure in order to provide effective protection with minimal area and power. The results obtained in the experimental process have been compared with the protection offered by TMR and Hamming codes, in order to prove the quality of the proposed solution.     

Improved throughput bit-serial multiplier for GF(2) fields

High throughput is a crucial factor in bit-serial GF(2^m) fields multiplication for a variety of different applications including cryptography, error coding detection and computer algebra. The throughput of a multiplier is dependent on the required number of clock cycles to reach a result and its critical path delay. However, most bit-serial GF(2^m) multipliers do not manage to reduce the required number of clock cycles below the threshold of m clock cycles without increasing dramatically their critical path delay. This increase is more evident if a multiplier is designed to be versatile. In this article, a new versatile bit-serial MSB multiplier for GF(2^m) fields is proposed that achieves a 50% increase on average in throughput when compared to other designs, with a very small increase in its critical path delay. This is achieved by an average 33.4% reduction in the required number of clock cycles below m. The proposed design can handle arbitrary bit-lengths upper bounded by m and is suitable for applications where the field order may vary.     

Formation of five- and six-membered heterocyclic rings under radical cyclisation conditions

This review describes the formation of five- and six-membered heterocyclic rings in various organic molecules by radical cyclisation and covers mostly the literature published in 2005.     

Factors contributing to the uncertainty in circumaural earphone calibration for audiometric testing

This paper describes important factors that need to be considered when determining the uncertainty in the calibration of the HDA200 circumaural earphones which are used in audiometric and psychoacoustic tests. This paper describes the instruments that were used, the procedures and the results of the measurements. Each of these measurements generated an uncertainty component and the final calculus of the total uncertainty was computed using standard procedures. This paper highlights the necessity for researches on the contribution that the artificial ears have on the uncertainty and establishes a calibration method.